According to Section 5.1.6 of TS 24.229, version 5, upon a mobile device receiving a 380 (Alternative Service) response with a <type> child element set to “emergency”, the mobile device is to automatically attempt an emergency call setup over the CS domain. If the emergency call setup is successful, then an emergency call is established for the mobile device. The mobile device normally receives the 380 response in response to transmitting an invite request message to the network. Therefore, by transmitting the invite request message, the mobile device can trigger the process of establishing an emergency call in the event that there is an emergency.